The blood pressure of a person is presently used as an important factor in determining the overall health of an individual. Further, it is often important either to record the blood pressure of an individual at a given time during the day or to record the variations in blood pressure throughout the day. Presently, blood pressure testing devices are available that are worn for extended periods, such as 24 to 48 hours. The blood pressure is taken and recorded on a regular basis throughout this extended period. In a typical blood pressure monitoring program, the patient wears a blood pressure cuff the entire monitoring period. An electronic system tests and records the blood pressure of the person every 20 or so minutes throughout the monitoring period. A small air pressure pump, electronic control, sensors and recorder are provided which pump up the cuff and record the blood pressure at the selected timed intervals.
The cuff often has sensors to perform the function of determining the blood pressure. It is therefore important that the cuff not rotate excessively so that the sensors and bladder are in the correct position to obtain an accurate reading of the blood pressure.
The individual wearing the blood pressure cuff is required to wear the cuff for the entire test period and keep it in the correct position so that the blood pressure readings are accurate. Unfortunately, during this extended period of 24 to 48 hours, the blood pressure cuff tends to slip down or move from its correct position on the arm. This is because during those intervals when a blood pressure reading is not being taken, the blood pressure cuff is deflated and fits more loosely around the arm.
It the cuff is worn for an extended period of time, it is not inflated most of the time. The only force acting to prevent the cuff from moving is the friction from contact with the arm and the full weight of the cuff is borne by the arm. Further, the tightness of the fit depends upon the circumference of the patient's arm. As the person flexes and stretches his arm, the circumference and shape of the arm will change and thus the fit of the cuff around the arm will vary throughout the day.
One solution is to wrap the cuff tightly around the arm when the cuff is not inflated. This is not satisfactory as it creates discomfort and the tightness of the fit will change as the person moves his arm. Further, the weight of the cuff is still borne solely by the arm in the general region of where the measurement is taken.
The problem of movement of the blood pressure cuff is particularly acute in overweight people. It is not uncommon for a person, particularly if he is overweight, to have a somewhat larger circumference at the top of his arm towards the shoulder than the circumference towards the elbow, gradually decreasing from the shoulder down. Thus, the arm of the person is in the shape of an inverted cone. To deal with this, the blood pressure cuff for such an individual may be made in the shape of an inverted cone so as to more closely fit the contour of the arm. However, this does not solve the problem of downward slipping or rotating of the cuff. The result is that an inverted cone (the arm) has another inverted cone (the cuff) wrapped around it, which will easily slip downward.
Another solution is to tape the cuff in position on the arm. While this does provide some additional support, it is not a satisfactory solution. The tape may contain a skin irritant which causes great discomfort to the skin while being worn. Further, when the tape is removed, there is discomfort from the pulling of hairs on the person's arms. Further, the tape often becomes loose if the person is moving his arm frequently or if the person has an oily skin or begins to perspire.